There are systems that can detect a failure of a communication system. In the event that one of the communication systems fails, another communication system can take over for the failed communication system. Some systems can mirror every communication that is sent and then resume existing communications based on detecting a failure. However, where the failover communication system is distributed to provide a more robust solution, mirroring does not work effectively due to delays in a network.
The Session Initiation Protocol (SIP) usually works in a distributed environment. Existing SIP solutions can detect a failover and redirect new SIP sessions to the failover communication system. However, if an existing SIP session has already been established, with existing solutions, the existing SIP session will time out and fail. Failing an existing SIP session is not an ideal solution. What is needed is a way to provide solutions that will failover an established SIP session.